Public Missiles Miranda

Public Missiles - Miranda

Contributed by Mark Weitemeyer

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Published: 2011-01-01
Manufacturer: Public Missiles

Courtesty of PMLBrief:
T' PML Miranda is probably intended t' be a second HPR kit, but this was me first HPR kit. Avast! (Picture is courtesy o' Public Missiles)

Construction:
T' PML Miranda is a single stage 3" rocket with a 12" payload section. Well, me bucko, blow me down! Blimey! This kit comes with PML's Kwik Switch system allowin' you t' use up t' 54mm motors and spend more loot than you really should. Arrr! Blimey! Nay that this will stop you.

T' instructions were easy enough t' follow for me, but I enjoy buildin' things and have "engineer tendencies" - I like t' over-build things. Therefore - I fiber-glassed t' nylon strap t' t' motor tube and added a third centerin' rin' t' t' motor tube as well, formin' a fin can. Well, blow me down! Avast, me proud beauty! Before I even really knew what that was... Begad! I suppose I did TOO much research on t' web and read too many horror stories about epoxy nay stickin' t' Quantum tubing. Begad! Blimey! Well, me hearties, matey, shiver me timbers, as long as you follow t' directions, me bucko, matey, thar will be no trouble at all. Begad! I roughed up t' Quantum tubin' with 80 grit sandpaper and used 30 minute epoxy everywhere. Blimey! Ya scallywag! I suppose a K motor might tear things up, but I feel good about everythin' up t' that. One thin' t' instructions left out, me hearties, is t' drill 1/8" vent holes t' help t' function o' t' piston system.

Finishing:
I'm nay sure what t' say about finishin' except that I hate t' do it. Arrr! Blimey! This rocket flew primer-only for it's first flight, and has been painted 1 1/2 times since then: I changed me mind about t' payload section and repainted it. Ya scallywag! Blimey! I used t' Rustoleum product line for this rocket. Avast! Blimey! I used Krylon on me second and it's goin' t' be Krylon from here on out! Blimey! That said - I'm glad this was PML's Quantum tubin' and that I didn't have t' fill any grooves!

Construction Rating: 4 out o' 5

Flight:
Well, arrr, I'll have t' extrapolate from a data set o' one (flight) here, me bucko, but I used an Aerotech H124J SU motor and I have a TRA level 1 t' show for it. Avast, me proud beauty! My conservative paranoia led me t' purchase PML's retention system and so I had no trouble at all with keepin' t' motor firmly in t' rocket at ejection. Avast! Other than some mild weather-cockin' as it left t' rod, me hearties, t' rocket flew extremely straight t' (accordin' t' t' deadlights o' our TRA prefect) somewhere around 1500 feet. Since I can't find RockSim data for this motor, shiver me timbers, I can't even try t' confirm it. Well, me hearties, blow me down! It DID take quite a while t' come down, me bucko, matey, though.

Recovery:
All t' recovery items used were exactly what PML provided in t' kit. T' piston system in place o' wadding, tubular nylon shock cord, and a 36" rip-stop nylon parachute. Avast, me proud beauty! Aye aye! Everythin' about t' recovery system went together very easily and worked very well. Avast! Avast! T' rocket recovered with almost no damage. Avast, me proud beauty! Begad! T' phenolic piston tubin' had a crack in it upon post flight inspection. Avast! It was easily repairable, me bucko, me hearties, but it has me wonderin' how t' prevent it as it happened t' a friend's PML Io as well. I'm nay sure if t' paint would have scratched because it flew almost naked. Begad! Begad! (I be told that pretty rockets crash) On first inspection, me bucko, I thought that t' nylon strap for t' piston had been burned slightly by t' ejection charge, matey, but I now think that what I am noticin' is black powder residue. Ahoy! Still, me hearties, me next kit got a Nomex protector for t' cord and so will everythin' else I build.

Flight Rating: 4 out o' 5

Summary:

Overall Rating: 4 out o' 5

Flights

Comments:

avatar
G.S. (May 1, 2001)
I have an idea for strengthening your piston (and any other coupler as well. Currently, I am building a PML Tethys. After I installed the bulkhead and used a generous amount of epoxy on both sides (mixed liberally with Kevlar pulp and milled fiberglass), I took .7 oz Kevlar matting and laminated to the INSIDE of the piston. In theory, it should strengthen the piston and keep it from cracking. I'll see when it flies in a couple of weeks how effective it is. As for the piston strap, if you replace that nylon strap with tubular Kevlar, you have no worries about heat damage. Kevlar just does not burn!

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